Protecting data integrity in de-duplicated storage environments in combination with software defined native raid

ABSTRACT

A mechanism is provided in a data processing system for securing data integrity in de-duplicated storage environments in combination with software defined native redundant array of independent disks (RAID). The mechanism receives a data portion to write to storage, divides the data portion into a plurality of chunks, and identifies a given chunk within the plurality of chunks for de-duplication. The mechanism increment a de-duplication counter for the given chunk and determines a RAID level for the given chunk based on a value of the de-duplication counter. The mechanism stores the given chunk based on the determined RAID level.

BACKGROUND

The present application relates generally to an improved data processingapparatus and method and more specifically to mechanisms for protectingdata integrity in de-duplicated storage environments in combination withsoftware defined native RAID.

RAID (redundant array of independent disks) is a data storagevirtualization technology that combines multiple disk drive componentsinto a single logical unit for the purposes of data redundancy orperformance improvement. RAID systems distribute data across the drivesin one of several ways, referred to as RAID levels, depending on thespecific level of redundancy and performance required.

A number of standard schemes have evolved. These are called levels.Originally, there were five RAID levels, but many variations haveevolved—notably several nested levels and many non-standard levels. RAIDlevels and their associated data formats are standardized by the StorageNetworking Industry Association (SNIA) in the Common RAID Disk DriveFormat (DDF) standard:

RAID 0 consists of striping, without mirroring or parity. The capacityof a RAID 0 volume is the sum of the capacities of the disks in the set,the same as with a spanned volume. There is no added redundancy forhandling disk failures, just as with a spanned volume. Thus, failure ofone disk causes the loss of the entire RAID 0 volume, with reducedpossibilities of data recovery when compared to a broken spanned volume.Striping distributes the contents of files roughly equally among alldisks in the set, which makes concurrent read or write operations on themultiple disks almost inevitable and results in performanceimprovements. The concurrent operations make the throughput of most readand write operations equal to the throughput of one disk multiplied bythe number of disks. Increased throughput is the big benefit of RAID 0versus spanned volume.

RAID 1 consists of data mirroring, without parity or striping. Data iswritten identically to two or more drives, thereby producing a “mirroredset” of drives. Thus, any read request can be serviced by any drive inthe set. If a request is broadcast to every drive in the set, it can beserviced by the drive that accesses the data first (depending on seektime and rotational latency), improving performance. Sustained readthroughput, if the controller or software is optimized for it,approaches the sum of throughputs of every drive in the set, just as forRAID 0. Actual read throughput of most RAID 1 implementations is slowerthan the fastest drive. Write throughput is always slower because everydrive must be updated, and the slowest drive limits the writeperformance. The array continues to operate as long as at least onedrive is functioning.

RAID 5 consists of block-level striping with distributed parity. RAID 5requires that all drives but one be present to operate. Upon failure ofa single drive, subsequent reads can be calculated from the distributedparity such that no data are lost. RAID 5 requires at least three disks.

RAID 6 consists of block-level striping with double distributed parity.Double parity provides fault tolerance up to two failed drives. Thismakes larger RAID groups more practical, especially forhigh-availability systems, as large -capacity drives take longer torestore. RAID 6 requires a minimum of four disks. As with RAID 5, asingle drive failure results in reduced performance of the entire arrayuntil the failed drive has been replaced. With a RAID 6 array, usingdrives from multiple sources and manufacturers, it is possible tomitigate most of the problems associated with RAID 5. The larger thedrive capacities and the larger the array size, the more important itbecomes to choose RAID 6 instead of RAID 5.

RAID 1+0, also referred to as RAID 10, creates a striped set from aseries of mirrored drives. The array can sustain multiple drive lossesso long as no mirror loses all its drives.

Software RAID implementations are now provided by many operatingsystems. Software RAID can be implemented as a layer that abstractsmultiple devices, thereby providing a single virtual device, a moregeneric logical volume manager, a component of the file system, or alayer that sits above any file system and provides parity protection touser data. Some advanced file systems are designed to organize dataacross multiple storage devices directly without needing the help of athird-party logical volume manager. The General Parallel File System(GPFS), initially developed by IBM for media streaming and scalableanalytics, supports de -clustered RAID protection schemes up to n+3. Aparticularity is the dynamic rebuilding priority which runs with lowimpact in the background until a data chunk hits n+0 redundancy, inwhich case this chunk is quickly rebuilt to at least n+1. On top, GPFSsupports metro-distance RAID 1.

In computing, data deduplication is a specialized data compressiontechnique for eliminating duplicate copies of repeating data. Thistechnique is used to improve storage utilization and can also be appliedto network data transfers to reduce the number of bytes that must besent. In the deduplication process, unique chunks of data, or bytepatterns, are identified and stored during a process of analysis. As theanalysis continues, other chunks are compared to the stored copy andwhenever a match occurs, the redundant chunk is replaced with a smallreference that points to the stored chunk. Given that the same bytepattern may occur dozens, hundreds, or even thousands of times (thematch frequency is dependent on the chunk size), the amount of data thatmust be stored or transferred can be greatly reduced.

SUMMARY

In one illustrative embodiment, a method, in a data processing system,is provided for securing data integrity in de-duplicated storageenvironments in combination with software defined native redundant arrayof independent disks (RAID). The method comprises receiving a dataportion to write to storage, dividing the data portion into a pluralityof chunks, and identifying a given chunk within the plurality of chunksfor de-duplication. The method further comprises incrementing ade-duplication counter for the given chunk and determining a RAID levelfor the given chunk based on a value of the de-duplication counter. Themethod further comprises storing the given chunk based on the determinedRAID level.

In other illustrative embodiments, a computer program product comprisinga computer useable or readable medium having a computer readable programis provided. The computer readable program, when executed on a computingdevice, causes the computing device to perform various ones of, andcombinations of, the operations outlined above with regard to the methodillustrative embodiment.

In yet another illustrative embodiment, a system/apparatus is provided.The system/apparatus may comprise one or more processors and a memorycoupled to the one or more processors. The memory may compriseinstructions which, when executed by the one or more processors, causethe one or more processors to perform various ones of, and combinationsof, the operations outlined above with regard to the method illustrativeembodiment.

These and other features and advantages of the present invention will bedescribed in, or will become apparent to those of ordinary skill in theart in view of, the following detailed description of the exampleembodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, as well as a preferred mode of use and further objectivesand advantages thereof, will best be understood by reference to thefollowing detailed description of illustrative embodiments when read inconjunction with the accompanying drawings, wherein:

FIG. 1 depicts a cloud computing node according to an illustrativeembodiment;

FIG. 2 depicts a cloud computing environment according an illustrativeembodiment;

FIG. 3 depicts abstraction model layers according to an illustrativeembodiment;

FIG. 4 depicts storage with data de-duplication in accordance with anillustrative embodiment;

FIG. 5 is a block diagram of a software defined RAID data managementmodule in accordance with an illustrative embodiment;

FIG. 6 shows an example mapping of predefined RAID levels for numbers ofde-duplications in accordance with an illustrative embodiment;

FIG. 7 shows an example mapping of predefined performance levels fornumbers of de-duplications in accordance with an illustrativeembodiment; and

FIG. 8 is a flowchart illustrating operation of a data management modulefor securing data integrity in de-duplicated storage environments withsoftware defined native RAID in accordance with an illustrativeembodiment.

DETAILED DESCRIPTION

The illustrative embodiments provide mechanisms for protecting dataintegrity in de-duplicated storage environments in combination withsoftware defined native RAID. The illustrative embodiments providemechanisms for dynamic creation and data placement on different RAIDprotection levels. The illustrative embodiments place highly importantdata, i.e., highly de-duplicated data, on higher RAID levels and toplace less important data, i.e., less de-duplicated data, on lower RAIDlevels within an acceptable level of investment for data protection. Inother embodiments, mechanisms perform dynamic data placement betweendifferent performance pools.

Before beginning the discussion of the various aspects of theillustrative embodiments, it should first be appreciated that throughoutthis description the term “mechanism” will be used to refer to elementsof the present invention that perform various operations, functions, andthe like. A “mechanism,” as the term is used herein, may be animplementation of the functions or aspects of the illustrativeembodiments in the form of an apparatus, a procedure, or a computerprogram product. In the case of a procedure, the procedure isimplemented by one or more devices, apparatus, computers, dataprocessing systems, or the like. In the case of a computer programproduct, the logic represented by computer code or instructions embodiedin or on the computer program product is executed by one or morehardware devices in order to implement the functionality or perform theoperations associated with the specific “mechanism.” Thus, themechanisms described herein may be implemented as specialized hardware,software executing on general purpose hardware, software instructionsstored on a medium such that the instructions are readily executable byspecialized or general purpose hardware, a procedure or method forexecuting the functions, or a combination of any of the above.

The present description and claims may make use of the terms “a,” “atleast one of,” and “one or more of” with regard to particular featuresand elements of the illustrative embodiments. It should be appreciatedthat these terms and phrases are intended to state that there is atleast one of the particular feature or element present in the particularillustrative embodiment, but that more than one can also be present.That is, these terms/phrases are not intended to limit the descriptionor claims to a single feature/element being present or require that aplurality of such features/elements be present. To the contrary, theseterms/phrases only require at least a single feature/element with thepossibility of a plurality of such features/elements being within thescope of the description and claims.

In addition, it should be appreciated that the following descriptionuses a plurality of various examples for various elements of theillustrative embodiments to further illustrate example implementationsof the illustrative embodiments and to aid in the understanding of themechanisms of the illustrative embodiments. These examples intended tobe non-limiting and are not exhaustive of the various possibilities forimplementing the mechanisms of the illustrative embodiments. It will beapparent to those of ordinary skill in the art in view of the presentdescription that there are many other alternative implementations forthese various elements that may be utilized in addition to, or inreplacement of, the examples provided herein without departing from thespirit and scope of the present invention.

It is understood in advance that although this disclosure includes adetailed description on cloud computing, implementation of the teachingsrecited herein are not limited to a cloud computing environment. Rather,embodiments of the present invention are capable of being implemented inconjunction with any other type of computing environment now known orlater developed.

Cloud computing is a model of service delivery for enabling convenient,on-demand network access to a shared pool of configurable computingresources (e.g. networks, network bandwidth, servers, processing,memory, storage, applications, virtual machines, and services) that canbe rapidly provisioned and released with minimal management effort orinteraction with a provider of the service. This cloud model may includeat least five characteristics, at least three service models, and atleast four deployment models.

Characteristics are as Follows:

On-demand self-service: a cloud consumer can unilaterally provisioncomputing capabilities, such as server time and network storage, asneeded automatically without requiring human interaction with theservice's provider.

Broad network access: capabilities are available over a network andaccessed through standard mechanisms that promote use by heterogeneousthin or thick client platforms (e.g., mobile phones, laptops, and PDAs).

Resource pooling: the provider's computing resources are pooled to servemultiple consumers using a multi-tenant model, with different physicaland virtual resources dynamically assigned and reassigned according todemand. There is a sense of location independence in that the consumergenerally has no control or knowledge over the exact location of theprovided resources but may be able to specify location at a higher levelof abstraction (e.g., country, state, or datacenter).

Rapid elasticity: capabilities can be rapidly and elasticallyprovisioned, in some cases automatically, to quickly scale out andrapidly released to quickly scale in. To the consumer, the capabilitiesavailable for provisioning often appear to be unlimited and can bepurchased in any quantity at any time.

Measured service: cloud systems automatically control and optimizeresource use by leveraging a metering capability at some level ofabstraction appropriate to the type of service (e.g., storage,processing, bandwidth, and active user accounts). Resource usage can bemonitored, controlled, and reported providing transparency for both theprovider and consumer of the utilized service.

Service Models are as Follows:

Software as a Service (SaaS): the capability provided to the consumer isto use the provider's applications running on a cloud infrastructure.The applications are accessible from various client devices through athin client interface such as a web browser (e.g., web-based email). Theconsumer does not manage or control the underlying cloud infrastructureincluding network, servers, operating systems, storage, or evenindividual application capabilities, with the possible exception oflimited user-specific application configuration settings.

Platform as a Service (PaaS): the capability provided to the consumer isto deploy onto the cloud infrastructure consumer-created or acquiredapplications created using programming languages and tools supported bythe provider. The consumer does not manage or control the underlyingcloud infrastructure including networks, servers, operating systems, orstorage, but has control over the deployed applications and possiblyapplication hosting environment configurations.

Infrastructure as a Service (IaaS): the capability provided to theconsumer is to provision processing, storage, networks, and otherfundamental computing resources where the consumer is able to deploy andrun arbitrary software, which can include operating systems andapplications. The consumer does not manage or control the underlyingcloud infrastructure but has control over operating systems, storage,deployed applications, and possibly limited control of select networkingcomponents (e.g., host firewalls).

Deployment Models are as Follows:

Private cloud: the cloud infrastructure is operated solely for anorganization It may be managed by the organization or a third party andmay exist on-premises or off-premises.

Community cloud: the cloud infrastructure is shared by severalorganizations and supports a specific community that has shared concerns(e.g., mission, security requirements, policy, and complianceconsiderations). It may be managed by the organizations or a third partyand may exist on-premises or off -premises.

Public cloud: the cloud infrastructure is made available to the generalpublic or a large industry group and is owned by an organization sellingcloud services.

Hybrid cloud: the cloud infrastructure is a composition of two or moreclouds (private, community, or public) that remain unique entities butare bound together by standardized or proprietary technology thatenables data and application portability (e.g., cloud bursting for loadbalancing between clouds).

A cloud computing environment is service oriented with a locus onstatelessness, low coupling, modularity, and semantic interoperability.At the heart of cloud computing is an infrastructure comprising anetwork of interconnected nodes.

Referring now to FIG. 1, a schematic of an example of a cloud computingnode is shown. Cloud computing node 10 is only one example of a suitablecloud computing node and is not intended to suggest any limitation as tothe scope of use or functionality of embodiments of the inventiondescribed herein. Regardless, cloud computing node 10 is capable ofbeing implemented and/or performing any of the functionality set forthhereinabove.

In cloud computing node 10 there is a computer system/server 12, whichis operational with numerous other general purpose or special purposecomputing system environments or configurations. Examples of well-knowncomputing systems, environments, and/or configurations that may besuitable for use with computer system/server 12 include, but are notlimited to, personal computer systems, server computer systems, thinclients, thick clients, handheld or laptop devices, multiprocessorsystems, microprocessor-based systems, set top boxes, programmableconsumer electronics, network PCs, minicomputer systems, mainframecomputer systems, and distributed cloud computing environments thatinclude any of the above systems or devices, and the like.

Computer system/server 12 may be described in the general context ofcomputer system executable instructions, such as program modules, beingexecuted by a computer system. Generally, program modules may includeroutines, programs, objects, components, logic, data structures, and soon that perform particular tasks or implement particular abstract datatypes. Computer system/server 12 may be practiced in distributed cloudcomputing environments where tasks are performed by remote processingdevices that are linked through a communications network. In adistributed cloud computing environment, program modules may be locatedin both local and remote computer system storage media including memorystorage devices.

As shown in FIG. 1, computer system/server 12 in cloud computing node 10is shown in the form of a general-purpose computing device. Thecomponents of computer system/server 12 may include, but are not limitedto, one or more processors or processing units 16, a system memory 28,and a bus 18 that couples various system components including systemmemory 28 to processor 16.

Bus 18 represents one or more of any of several types of bus structures,including a memory bus or memory controller, a peripheral bus, anaccelerated graphics port, and a processor or local bus using any of avariety of bus architectures. By way of example, and not limitation,such architectures include Industry Standard Architecture (ISA) bus,Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, VideoElectronics Standards Association (VESA) local bus, and PeripheralComponent Interconnects (PCI) bus.

Computer system/server 12 typically includes a variety of computersystem readable media. Such media may be any available media that isaccessible by computer system/server 12, and it includes both volatileand non-volatile media, removable and non-removable media.

System memory 28 can include computer system readable media. in the formof volatile memory, such as random access memory (RAM) 30 and/or cachememory 32. Computer system/server 12 may further include otherremovable/non -removable, volatile/non-volatile computer system storagemedia. By way of example only, storage system 34 can be provided forreading from and writing to a non -removable, non-volatile magneticmedia (not shown and typically called a “hard drive”). Although notshown, a magnetic disk drive for reading from and writing to aremovable, non-volatile magnetic disk (e.g., a “floppy disk”), and anoptical disk drive for reading from or writing to a removable,non-volatile optical disk such as a CD-ROM, DVD-ROM or other opticalmedia can be provided. In such instances, each can be connected to bus18 by one or more data media interfaces. As will be further depicted anddescribed below, memory 28 may include at least one program producthaving a set (e.g., at least one) of program modules that are configuredto carry out the functions of embodiments of the invention.

Program/utility 40, having a set (at least one) of program modules 42,may be stored in memory 28 by way of example, and not limitation, aswell as an operating system, one or more application programs, otherprogram modules, and program data. Each of the operating system, one ormore application programs, other program modules, and program data orsome combination thereof, may include an implementation of a networkingenvironment. Program modules 42 generally carry out the functions and/ormethodologies of embodiments of the invention as described herein.

Computer system/server 12 may also communicate with one or more externaldevices 14 such as a keyboard, a pointing device, a display 24, etc.;one or more devices that enable a user to interact with computersystem/server 12; and/or any devices (e.g., network card, modem, etc.)that enable computer system/server 12 to communicate with one or moreother computing devices. Such communication can occur via Input/Output(I/O) interfaces 22. Still yet, computer system/server 12 cancommunicate with one or more networks such as a local area network(LAN), a general wide area network (WAN), and/or a public network (e.g.,the Internet) via network adapter 20. As depicted, network adapter 20communicates with the other components of computer system/server 12 viabus 18. It should be understood that although not shown, other hardwareand/or software components could be used in conjunction with computersystem/server 12. Examples, include, but are not limited to: microcode,device drivers, redundant processing units, external disk drive arrays,RAID systems, tape drives, and data archival storage systems, etc.

Referring now to FIG. 2, illustrative cloud computing environment 50 isdepicted. As shown, cloud computing environment 50 comprises one or morecloud computing nodes 10 with which local computing devices used bycloud consumers, such as, for example, personal digital assistant (PDA)or cellular telephone 54A, desktop computer 54B, laptop computer 54C,and/or automobile computer system 54N may communicate. Nodes 10 maycommunicate with one another. They may be grouped (not shown) physicallyor virtually, in one or more networks, such as Private, Community,Public, or Hybrid clouds as described hereinabove, or a combinationthereof. This allows cloud computing environment 50 to offerinfrastructure, platforms and/or software as services for which a cloudconsumer does not need to maintain resources on a local computingdevice. It is understood that the types of computing devices 54A-N shownin FIG. 2 are intended to be illustrative only and that computing nodes10 and cloud computing environment 50 can communicate with any type ofcomputerized device over any type of network and/or network addressableconnection (e.g., using a web browser).

Referring now to FIG. 3, a set of functional abstraction layers providedby cloud computing environment 50 (FIG. 2) is shown. It should beunderstood in advance that the components, layers, and functions shownin FIG. 3 are intended to be illustrative only and embodiments of theinvention are not limited thereto. As depicted, the following layers andcorresponding functions are provided:

Hardware and software layer 60 includes hardware and softwarecomponents. Examples of hardware components include mainframes, in oneexample IBM® zSeries® systems; RISC (Reduced Instruction Set Computer)architecture based servers, in one example IBM pSeries® systems; IBMxSeries® systems; IBM BladeCenter® systems; storage devices; networksand networking components. Examples of software components includenetwork application server software, in one example IBM WebSphere®application server software; and database software, in one example IBMDB2® database software. (IBM, zSeries, pSeries, xSeries, BladeCenter,WebSphere, and DB2 are trademarks of International Business MachinesCorporation registered in many jurisdictions worldwide).

Virtualization layer 62 provides an abstraction layer from which thefollowing examples of virtual entities may be provided: virtual servers;virtual storage; virtual networks, including virtual private networks;virtual applications and operating systems; and virtual clients.

In one example, management layer 64 may provide the functions describedbelow. Resource provisioning provides dynamic procurement of computingresources and other resources that are utilized to perform tasks withinthe cloud computing environment. Metering and Pricing provide costtracking as resources are utilized within the cloud computingenvironment, and billing or invoicing for consumption of theseresources. In one example, these resources may comprise applicationsoftware licenses. Security provides identity verification for cloudconsumers and tasks, as well as protection for data and other resources.User portal provides access to the cloud computing environment forconsumers and system administrators. Service level management providescloud computing resource allocation and management such that requiredservice levels are met. Service Level Agreement (SLA) planning andfulfillment provide pre-arrangement for, and procurement of, cloudcomputing resources for which a future requirement is anticipated inaccordance with an SLA.

Workloads layer 66 provides examples of functionality for which thecloud computing environment may be utilized. Examples of workloads andfunctions which may be provided from this layer include: mapping andnavigation; software development and lifecycle management; virtualclassroom education delivery; and data analytics processing; transactionprocessing.

FIG. 4 depicts storage with data de-duplication in accordance with anillustrative embodiment. The amount of digitally stored information isdramatically increasing. Recent studies estimate that this growth willcontinue by a factor of approximately 40 within the next ten years. Inorder to mitigate this dramatic growth, one may use data de-duplicationmethods to eliminate or reduce the amount of duplicated data.

As shown in FIG. 4, chunker 410 is an algorithm executing as software ina host or as software or firmware in a storage controller. Chunker 410receives a byte stream of data to be written to storage 420 and dividesthe byte stream into chunks. The byte stream may comprise files orblocks of data, for example. A chunk may be a file, a block, multipleblocks, etc. The chunks may be a fixed or variable size. Chunker 410determines an identity characteristic for each chunk. Chunker 410 maydetermine the identity using a hash function, for example.

When chunker 410 identifies an incoming block as a duplicate of apreviously stored block, the de-duplication algorithm adds only apointer to the previously physically stored block to the respectivemetadata. The de-duplication algorithm stores non-identical chunks tophysical storage 420. The de-duplication algorithm may also usecompression when storing a chunk to physical storage 420.

In case of corruption or disk failure, the toss of data is magnified bythe level of de-duplication. That is, when a chunk of data in physicalstorage 420 is compromised, every chunk referencing the physicallystored chunk is also compromised. The better the de-duplication ratiois, the higher are the chances for “rot data” incidents to impact largernumbers of files and deem them all corrupted or lost. “Rot data” is anincident where “bit flips” (from 1 to 0 or vice versa) occurspontaneously on the storage and, as such, destroy data integrity.

To protect data from corruption and disk failures, one may establish astorage system with RAID level 5. RAID (redundant array of independentdisks) is a data storage virtualization technology that combinesmultiple disk drive components into a single logical unit for thepurposes of data redundancy or performance improvement. RAID 5 consistsof block-level striping with distributed parity. This is considered anacceptable level of investment for data integrity. Double disk errorsnot protected by RAID 5 result in a huge amount of corrupt or lost data.

RAID technology has grown from a server option to a data protectionrequirement. The first implementations of RAID in 1990 were veryexpensive controller boards with high performance input/output (I/O)processors that were as powerful as the host central processing unit(CPU). At that time, when hardware -based RAID solutions were the onlyoption, the cost of a RAID controller limited the usage to high-pricedservers. Today, RAID is found everywhere—from an operating systemsoftware feature to a stand-alone controller providing advanced dataintegrity in high-end storage area networks. RAID can be found in mobileenvironments such as laptops, as well as desktops, workstations,servers, and external enclosures with a large number of hard diskdrives.

As an example, IBM® General Parallel File System (GPFS™) Native RAID isa software implementation of storage RAID technologies with GPFS. GPFS™Native RAID integrates the functionality of an advanced storagecontroller into the GPFS Network Shared Disk (NSD) server. Unlike anexternal storage controller, where configuration, logical unit (LUN)definition, and maintenance are beyond the control of GPFS, GPFS NativeRAID takes ownership of the disk array to directly match LUN definition,caching, and disk behavior to GPFS requirements. Sophisticated dataplacement and error correction algorithms deliver high levels of storagereliability, availability, serviceability, and performance.

The illustrative embodiments provide a mechanism to enhance therobustness of de-duplicated storage environments. The illustrativeembodiments use dynamic data RAID level definition depending on the datade-duplication information for each data chunk. The illustrativeembodiments combine the information of de -duplication into thesophisticated data placement engine within native RAID softwareimplementations.

The higher the de-duplication ratio, the greater the probability that alarge number of files are corrupted by a single chunk error or loss,e.g., when “bit flips” occur spontaneously on the storage device anddestroy data integrity. Higher RAID levels can protect against theseerrors but they will require more storage. This runs counter to thepurpose of de-duplication, which is to reduce the amount of requiredmore storage.

In accordance with the illustrative embodiment, dynamic software definedRAID levels effectively address this contradiction by placing importantdata at a higher RAID level than less important data. The level ofimportance for a particular piece of data is determined from thede-duplication information. The illustrative embodiments combine thede-duplication engine with the sophisticated data placement engine ofsoftware defined RAID.

FIG. 5 is a block diagram of a software defined RAID data managementmodule in accordance with an illustrative embodiment. Data managementmodule (DMM) 510 manages the combination of de-duplication engine 520,data placement engine 530, and software defined RAID engine 540. DMM 510captures information from de-duplication engine 520, such as the amountof de-duplication for each chunk. DMM 510 maps predefined thresholds onthe amount of de-duplication pointers to predefined RAID levels. FIG. 6shows an example mapping of predefined RAID levels for numbers ofde-duplications in accordance with an illustrative embodiment. In thedepicted example, chunks with zero to 1,000 de-duplications are mappedto RAID 5, chunks with 1,000 to 10,000 de-duplications are mapped toRAID 6, chunks with 10,000 to 100,000 de-duplications are mapped to RAID10, and chunks with greater than 100,000 de-duplications are mapped toRAID 1. The thresholds and mappings shown in FIG. 6 are examples toillustrate the aspects of the illustrative embodiments, and otherthresholds and mappings may be used within the spirit and scope of theillustrative embodiments.

In accordance with one embodiment, the predefined thresholds may be setthrough a configuration option of software defined RAID. DMM 510provides the required RAID levels to software defined RAID engine 540,which creates the RAID configurations in physical storage. Dataplacement engine 530 places chunks into physical storage. Depending onthe increase or decrease of de-duplication counters, which count thenumber of de-duplication pointers, data placement engine 530 migratesthe data into the appropriate RAID levels provided by software definedRAID engine 540 depending on the predefined thresholds within DMM 510.

Thus, the illustrative embodiments dynamically place important data athigh protection RAID levels with less important data placed at towerRAID levels. This results in significantly less storage being requiredto obtain the desired protection.

In addition, in accordance with one embodiment, DMM 510 dynamicallyadjusts the RAID levels and thresholds depending on data demand.Frequently accessed data would be protected at a higher RAID level asdata loss will have a greater impact on the storage user.

Furthermore, in addition to the above, in one embodiment, DMM 510defines performance levels for the different levels of de-duplication.Data placement engine 530 automatically migrates data to pre-definedperformance pools. FIG. 7 shows an example mapping of predefinedperformance levels for numbers of de -duplications in accordance with anillustrative embodiment. In the depicted example, chunks with zero to1,000 de-duplications are mapped to a low performance storage pool,chunks with 1,000 to 100,000 de-duplications are mapped to a mediumperformance storage pool, and chunks with greater than 100,000de-duplications are mapped to a high performance storage pool. Thethresholds and mappings shown in FIG. 7 are examples to illustrate theaspects of the illustrative embodiments, and other thresholds andmappings may be used within the spirit and scope of the illustrativeembodiments.

As shown in FIG. 7, DMM 510 places less duplicated data in a slowstorage pool, such as near line serial attached SCSI (small computersystem interface) (SAS) drives, and highly duplicated data in a faststorage pool, such as solid state disk (SSD).

One or more of the above procedures could be present in any giveninstance of software defined RAID.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD -ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Java, Smalltalk, C++ or the like,and conventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field -programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

FIG. 8 is a flowchart illustrating operation of a data management modulefor securing data integrity in de-duplicated storage environments withsoftware defined native RAID in accordance with an illustrativeembodiment. Operation begins (block 800), and the data management module(DMM) receives a data portion to write to storage (block 801). Ade-duplication engine divides the data portion into a plurality ofchunks (block 802) and identifies chunks for de-duplication (block 803).The de-duplication engine increments a de-duplication counter for eachde -duplicated chunk (block 804). The counter indicates a number ofreferences to a previously stored chunk in physical storage or, in otherwords, a number of de -duplications for the chunk.

A software defined RAID engine of the DMM then determines a RAID levelfor each chunk based on a value of the de-duplication counter (block805). In one embodiment, the DMM maintains a mapping of de-duplicationthresholds to RAID levels and the software defined RAID engine comparesthe value of the de -duplication counter to the thresholds. For example,if the value of the de-duplication counter for a given chunk is lessthan 1,000, then the software defined RAID engine assigns RAID level 5for the given chunk; if the value of the de-duplication counter for thegiven chunk is between 1,000 and 10,000, then the software defined RAIDengine assigns RAID level 6 for the given chunk; if the value of thecounter is between 10,000 and 100,000, then the software defined RAIDengine assigns RAID level 10; and, if the value of the counter isgreater than 100,000, then the software defined RAID engine assigns RAIDlevel 1.

Also, in one embodiment, a data placement engine of the DMM determines aperformance level for each chunk based on a value of the de-duplicationcounter (block 806). In one embodiment, the DMM maintains a mapping ofde -duplication thresholds to performance levels and the data placementengine compares the value of the de-duplication counter to thethresholds. For example, if the value of the de-duplication counter fora given chunk is less than 1,000, then the data placement engine assignsa low performance level for the given chunk and assigns the chunk to atow performance pool of storage; if the value of the de-duplicationcounter for the given chunk is between 1,000 and 100,000, then the dataplacement engine assigns a medium performance level for the given chunk;and, if the value of the counter is greater than 100,000, then the dataplacement engine assigns the given chunk to a high performance storagepool.

The DMM then stores a reference for each de-duplicated chunk and storeseach non-de-duplicated chunk to storage (block 807). The DMM thendetermines whether one or more chunks are to be migrated to a differentRAID level or a different performance pool based on a value of thede-duplication counter (block 808). For example, if the DMM increments ade-duplication counter for a given chunk in block 804 and the countercrosses a threshold, the DMM and the data placement engine migrate thechunk. If one or more chunks are to be migrated, the DMM and dataplacement engine migrate the one or more chunks with changing RAIDand/or performance level (block 809). Thereafter, or if no chunks are tobe migrated in block 808, operation ends (block 810).

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams amid/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

As noted above, it should be appreciated that the illustrativeembodiments may take the form of an entirely hardware embodiment, anentirely software embodiment or an embodiment containing both hardwareand software elements. In one example embodiment, the mechanisms of theillustrative embodiments are implemented in software or program code,which includes but is not limited to firmware, resident software,microcode, etc.

A data processing system suitable for storing and/or executing programcode will include at least one processor coupled directly or indirectlyto memory elements through a system bus. The memory elements can includelocal memory employed during actual execution of the program code, bulkstorage, and cache memories which provide temporary storage of at leastsome program code in order to reduce the number of times code must beretrieved from bulk storage during execution.

Input/output or I/O devices (including but not limited to keyboards,displays, pointing devices, etc.) can be coupled to the system eitherdirectly or through intervening I/O controllers. Network adapters mayalso be coupled to the system to enable the data processing system tobecome coupled to other data processing systems or remote printers orstorage devices through intervening private or public networks. Modems,cable modems and Ethernet cards are just a few of the currentlyavailable types of network adapters.

The description of the present invention has been presented for purposesof illustration and description, and is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the describedembodiments. The embodiment was chosen and described in order to bestexplain the principles of the invention, the practical application, andto enable others of ordinary skill in the art to understand theinvention for various embodiments with various modifications as aresuited to the particular use contemplated. The terminology used hereinwas chosen to best explain the principles of the embodiments, thepractical application or technical improvement over technologies foundin the marketplace, or to enable others of ordinary skill in the art tounderstand the embodiments disclosed herein.

What is claimed is:
 1. A method, in a data processing system, forsecuring data integrity in de -duplicated storage environments incombination with software defined native redundant array of independentdisks (RAID), the method comprising: receiving a data portion to writeto storage; dividing the data portion into a plurality of chunks;identifying a given chunk within the plurality of chunks forde-duplication; incrementing a de-duplication counter for the givenchunk; determining a RAID level for the given chunk based on a value ofthe de-duplication counter; and storing the given chunk based on thedetermined RAID level.
 2. The method of claim 1, wherein determining theRAID level for the given chunk comprises comparing the de-duplicationcounter to at least one threshold, wherein the at least one thresholdare mapped to corresponding RAID levels.
 3. The method of claim 2,wherein values of the de-duplication counter less than a first thresholdare mapped to RAID 5, wherein values of the de-duplication countergreater than the first threshold and less than a second threshold aremapped to RAID 6, wherein values of the de-duplication counter greaterthan the second threshold and less than a third threshold are mapped toRAID 10, and wherein values of the de -duplication counter greater thanthe third threshold are mapped to RAID
 1. 4. The method of 1, furthercomprising determining a performance level for the given chunk based onthe value of the de-duplication counter, wherein storing the given chunkcomprises storing the given chunk based on the determined RAID level andthe determined performance level.
 5. The method of claim 4, whereinstoring the given chunk comprises storing a reference to a previouslystored chunk in physical storage and migrating the previously storedchunk based on the determined RAID level.
 6. The method of claim 4,wherein determining the performance level for the given chunk comprisescomparing the de-duplication counter to at least one threshold, whereinthe at least one threshold are mapped to corresponding RAID levels. 7.The method of claim 6, wherein values of the de-duplication counter lessthan a first threshold are mapped to a low performance pool of storage,wherein values of the de-duplication counter greater than the firstthreshold and less than a second threshold are mapped to a mediumperformance pool of storage, and wherein values of the de-duplicationcounter greater than the second threshold are mapped to a highperformance pool of storage.
 8. The method of claim 1, furthercomprising dynamically adjusting the RAID level of the given chunk basedon data demand.
 9. The method of claim 1, wherein storing the givenchunk comprises storing a reference to a previously stored chunk inphysical storage and migrating the previously stored chunk based on thedetermined RAID level.
 10. A computer program product comprising acomputer readable storage medium having a computer readable programstored therein, wherein the computer readable program, when executed ona computing device, causes the computing device to: receive a dataportion to write to storage; divide the data portion into a plurality ofchunks; identify a given chunk within the plurality of chunks forde-duplication; increment a de-duplication counter for the given chunk;determine a RAID level for the given chunk based on a value of the de-duplication counter; and store the given chunk based on the determinedRAID level.
 11. The computer program product of claim 10, whereindetermining the RAID level for the given chunk comprises comparing thede-duplication counter to at least one threshold, wherein the at leastone threshold are mapped to corresponding RAID levels.
 12. The computerprogram product of claim 11, wherein values of the de -duplicationcounter less than a first threshold are mapped to RAID 5, wherein valuesof the de-duplication counter greater than the first threshold and lessthan a second threshold are mapped to RAID 6, wherein values of thede-duplication counter greater than the second threshold and less than athird threshold are mapped to RAID 10, and wherein values of thede-duplication counter greater than the third threshold are mapped toRAID
 1. 13. The computer program product of 10, wherein the computerreadable program further causes the computing device to determine aperformance level for the given chunk based on the value of thede-duplication counter, wherein storing the given chunk comprisesstoring the given chunk based on the determined RAID level and thedetermined performance level.
 14. The computer program product of claim13, wherein storing the given chunk comprises storing a reference to apreviously stored chunk in physical storage and migrating the previouslystored chunk based on the determined RAID level.
 15. The computerprogram product of claim 13, wherein determining the performance levelfor the given chunk comprises comparing the de-duplication counter to atleast one threshold, wherein the at least one threshold are mapped tocorresponding RAID levels.
 16. The computer program product of claim 15,wherein values of the de -duplication counter less than a firstthreshold are mapped to a low performance pool of storage, whereinvalues of the de-duplication counter greater than the first thresholdand less than a second threshold are mapped to a medium performance poolof storage, and wherein values of the de-duplication counter greaterthan the second threshold are mapped to a high performance pool ofstorage.
 17. The computer program product of claim 10, wherein thecomputer readable program further causes the computing device todynamically adjust the RAID level of the given chunk based on datademand.
 18. The computer program product of claim 10, wherein storingthe given chunk comprises storing a reference to a previously storedchunk in physical storage and migrating the previously stored chunkbased on the determined RAID level.
 19. An apparatus comprising: aprocessor; and a memory coupled to the processor, wherein the memorycomprises instructions which, when executed by the processor, cause theprocessor to: receive a data portion to write to storage; divide thedata portion into a plurality of chunks; identify a given chunk withinthe plurality of chunks for de-duplication; increment a de-duplicationcounter for the given chunk; determine a RAID level for the given chunkbased on a value of the de -duplication counter; and store the givenchunk based on the determined RAID level.
 20. The apparatus of 19,wherein the computer readable program further causes the computingdevice to determine a performance level for the given chunk based on thevalue of the de-duplication counter, wherein storing the given chunkcomprises storing the given chunk based on the determined RAID level andthe determined performance level.